Processing method of carbon molecular sieve

Abstract

The invention relates to the field of preparation of carbon molecular sieves, and particularly discloses a processing method of a carbon molecular sieve, which comprises the following steps: S1, crushing flower mud to obtain crushed powder; s2, weighing 30-40 parts by mass of the crushed powder, 10-15 parts by mass of resin oil, 15-25 parts by mass of tar and 25-35 parts by mass of water, and uniformly mixing and stirring to obtain a composite material; s3, extruding and carbonizing the composite material to obtain a semi-finished product, and adjusting pores of the semi-finished product to obtain the finished carbon molecular sieve which has the advantages of high particle uniformity, high compressive strength, high nitrogen yield and small air-nitrogen ratio.

Description

Technical Field

[0001] The present invention relates to the field of carbon molecular sieve preparation, and more specifically, to a method for processing carbon molecular sieve. Background Art

[0002] Carbon molecular sieve is a kind of columnar granular adsorbent with micropores on the surface and inside, which is made of coal, fruit shell, coconut shell or phenolic resin as the main raw materials, through grinding, kneading, extrusion molding, carbonization and other processes, and processed by special pore treatment technology.

[0003] Carbon molecular sieve has the ability to adsorb oxygen molecules in the air under normal temperature and pressure fluctuations, and can obtain nitrogen-rich gas. The ability to separate air depends on the different diffusion rates or different adsorption forces of various gases in the air in the micropores of the carbon molecular sieve.

[0004] The main element of carbon molecular sieve is carbon, and its appearance is a black columnar solid. It can be widely used in environmental protection, chemical industry, coal industry, electronics industry, food processing, hydrometallurgy, metal heat treatment, drug refining, petroleum industry, new energy, aerospace, transportation and storage.

[0005] Therefore, how to prepare a carbon molecular sieve with high particle uniformity, high compressive strength, high nitrogen yield and small air-nitrogen ratio is a problem to be solved. Summary of the invention

[0006] In order to prepare a carbon molecular sieve with high particle uniformity, high compressive strength, high nitrogen yield and low air-nitrogen ratio, the present application provides a processing method of a carbon molecular sieve.

[0007] The present application provides a method for processing a carbon molecular sieve, which adopts the following technical solution: A method for processing a carbon molecular sieve comprises the following steps: S1, crushing the flower mud to obtain crushed powder; S2, weigh 30-40 parts of crushed powder, 10-15 parts of resin oil, 15-25 parts of tar, and 25-35 parts of water according to the mass ratio, mix and stir evenly to obtain a composite material; S3. The composite material is extruded and carbonized to obtain a semi-finished product, and the semi-finished product is adjusted in pore size to obtain a finished carbon molecular sieve.

[0008] By adopting the above technical solution, after the flower mud is pulverized, the particle size of the flower mud is reduced, and the coarse-grained impurities are reduced from clogging the pores of the carbon molecular sieve in the subsequent carbonization. Moreover, after pulverization, the specific surface area increases and the surface activity enhances, making it easier to form uniformly distributed micropores during the carbonization process, meeting the threshold of the molecular sieve effect required for nitrogen-oxygen separation, and facilitating the penetration and adhesion of resin oil, tar, and water. By forming a uniform composite material, structural defects caused by uneven local adhesion during the carbonization process are avoided, thereby further ensuring the particle uniformity and compressive strength of the carbon molecular sieve.

[0009] The pulverized flower mud is mixed with resin oil, tar, and water. Utilizing the bonding effect of resin oil and tar, the pulverized materials are bonded to form a composite body, which can undergo polycondensation to form a three-dimensional cross-linked network during the high-temperature carbonization process, improving the bonding force between particles and thus enhancing the compressive strength. And with tar as the framework, during the carbonization process, amorphous carbon can be formed to fill the macropore defects, combined with resin oil, ensuring the pore uniformity while forming continuous pores in the carbon molecular sieve, further enhancing the mechanical strength of the carbon molecular sieve.

[0010] The volatile components in the resin oil orderly overflow during the carbonization stage, forming connected mesoporous channels. Combining with the micropores selectively covered by tar on the carbon layer, the probability of nitrogen being displaced by oxygen in the adsorption competition is reduced, and the nitrogen production rate is increased.

[0011] The hydrophobic carbon surface generated by the carbonization of tar reduces the competitive adsorption of water molecules to the pores, increasing the air-nitrogen ratio. Combining with the π-π stacking effect during the co-carbonization process of resin oil and flower mud to restrict the growth of the carbon layer, the pore size distribution is concentrated, and the air-nitrogen ratio is further reduced.

[0012] After the flower mud undergoes extrusion, carbonization, and pore adjustment, the carbon molecular sieve has the advantages of uniform particle distribution, high pore connectivity uniformity, low impurity content, and good compressive strength.

[0013] Preferably, for the step S1 of pulverizing the flower mud, the specific steps are as follows: The flower mud is preliminarily pulverized to obtain flower mud microparticles. A cellulose enzyme composite solution is added, and ultrasonic dispersion treatment is carried out for 30 - 40 min. Then it is heated to 80 - 100 °C for 6 - 10 min, and then ethanol is added for washing 2 - 3 times. The ethanol is filtered out, and then a hydrochloric acid solution with a concentration of 3 - 5% is added. After stirring evenly, the hydrochloric acid solution is filtered out, followed by washing with water, drying, and secondary ball milling and pulverization.

[0014] After the flower mud microparticles are mixed with the cellulose enzyme composite solution, the cellulose enzyme composite solution can not only quickly penetrate and evenly contact with the flower mud microparticles, but also the cellulose enzyme can selectively cut the glycosidic bond, reducing the cross-linking resistance of the flower mud fibers, promoting the penetration of resin oil and tar into the fiber network, forming a three-dimensional enhanced framework structure. After carbonization, the prepared carbon molecular sieve has a high compressive strength.

[0015] Cellulase can effectively decompose the cellulose component in the floral foam, convert it into substances that are more easily carbonized, thereby improving the utilization rate and conversion efficiency of the carbon source. The decomposition effect of cellulase helps to form more tiny channels and pores inside the floral foam, providing favorable conditions for the escape of gas and the formation of pore structure during the carbonization process, enabling the carbon molecular sieve to have a higher porosity and adsorption effect, and further improving the nitrogen yield and reducing the air-nitrogen ratio.

[0016] After treating with cellulase, heat up to inactivate the enzyme, then use ethanol washing to remove the inactivated cellulase as much as possible, and then utilize the penetration effect of hydrochloric acid solution to further dissolve the metal impurities in the floral foam. Substances such as metallic iron and aluminum are dissolved and separated from the floral foam, reducing the impurity content in the floral foam, reducing the blockage of the microporous structure by impurities, and the hydrochloric acid treatment can also remove the silicate impurities between cellulase and particles, promote the generation of through mesoporous channels, shorten the nitrogen diffusion path, improve the nitrogen yield, and reduce the air-nitrogen ratio; at the same time, after treating the floral foam with hydrochloric acid and cellulase, it can further eliminate the stress concentration points inside the particles, and the resin oil and tar can penetrate more evenly during the carbonization process, thereby improving the compressive strength of the carbon molecular sieve.

[0017] Preferably, in the S1, the carbon content of the floral foam is 75 - 80%, and the average particle size of the crushed powder is 1 - 2 μm.

[0018] By adopting the above technical scheme, limiting the carbon content of the floral foam and the average particle size of the crushed powder can further improve the compressive strength of the finished carbon molecular sieve, and improve the nitrogen yield and reduce the air-nitrogen ratio.

[0019] Preferably, the cellulase composite solution is prepared by the following method: Mix cetearyl alcohol and cellulase evenly according to a mass ratio of 1:2 - 4, then heat up to 50 - 52 °C and stir for 1 - 3 min, and then cool to room temperature to obtain a cellulase composite material; mix the cellulase composite material and water evenly according to a mass ratio of 1:60 - 80 to obtain a cellulase composite solution.

[0020] By adopting the above technical scheme, cetearyl alcohol and cellulase are mixed and heated to the melting point of cetearyl alcohol, so that the surface of cetearyl alcohol softens and melts to generate viscosity, further loading cellulase, and cellulase is evenly wrapped on the surface of cetearyl alcohol. Since cetearyl alcohol is insoluble in water, the cellulase in the prepared cellulase composite solution can be evenly dispersed, and the problems of enzyme aggregation and uneven contact with the floral foam are not likely to occur.

[0021] After the cellulase complex solution is mixed with the floral foam microparticles, ultrasonic dispersion is used to further promote the contact between the cellulase complex and the floral foam microparticles. The treatment time is limited to ensure that the cellulase decomposes the cellulose in the floral foam microparticles. Then, the temperature is raised to 80-100 °C, and the cellulase is inactivated. Cetearyl alcohol is completely melted and can carry the inactivated cellulase. With the subsequent washing with ethanol, cetearyl alcohol dissolves in ethanol. Utilizing the good lubricating fluidity of cetearyl alcohol, it can promote the detachment of the inactivated cellulase carried by cetearyl alcohol from the floral foam microparticles, thereby reducing the impurity content in the floral foam, improving the particle uniformity and nitrogen production rate of the carbon molecular sieve, and reducing the air-nitrogen ratio.

[0022] Preferably, the resin oil comprises the following raw materials in parts by weight: 86-92 parts of liquid phenolic resin, 4-6 parts of furfuryl alcohol resin, and 2-10 parts of polyethylene diamine solution.

[0023] By adopting the above technical solution, hydrogen bond networks can be formed between the amino groups in the polyethylene diamine solution and the hydroxyl groups in the furfuryl alcohol resin. After carbonization, the strength of the carbon molecular sieve is improved; and after the carbonization of polyethylene diamine, a nitrogen-doped skeleton can be generated inside and on the surface of the carbon molecular sieve. The pyridine-N structure formed on the nitrogen-doped carbon surface has the advantage of specific adsorption of nitrogen molecules, which can improve the nitrogen production rate; while the 3-4 nm mesoporous transition layer generated by the pyrolysis of furfuryl alcohol resin can connect micropores and macropores, thereby reducing the gas diffusion resistance and improving the adsorption capacity of the carbon molecular sieve, and thus reducing the air-nitrogen ratio.

[0024] The liquid phenolic resin, polyethylene diamine solution, and furfuryl alcohol resin are combined. Ammonia is gradually released after the temperature of polyethylene diamine is raised, improving the three-dimensional through microporous network of the carbon molecular sieve. Combined with the high-temperature carbonization of the benzene ring of phenolic resin to induce the oriented arrangement of graphite microcrystals, the nitrogen production rate of the carbon molecular sieve is improved and the air-nitrogen ratio is reduced; combined with furfuryl alcohol resin to reduce the frictional resistance between particles, further improving the particle uniformity of the carbon molecular sieve; and phenolic resin can form a dense protective film on the surface of the carbon molecular sieve to inhibit the micropore collapse caused by the airflow erosion and ensure the strength of the carbon molecular sieve.

[0025] Preferably, in S2, after the crushed material is mixed with water, a polyethylene diamine solution is added. After ultrasonic dispersion evenly, a liquid phenolic resin and a furfuryl alcohol resin are added and stirred evenly, and finally tar is added and stirred evenly to obtain a composite material.

[0026] By adopting the above technical solution, first, the crushed powder material is mixed with water, and then a polyethylene diamine solution is added. Utilizing the water-soluble penetration effect of polyethylene diamine and cooperating with ultrasonic dispersion, it promotes the uniform contact between polyethylene diamine and the crushed powder material. During the carbonization heating process, polyethylene diamine forms a nitrogen-doped structure on the surface of the carbon matrix, and the gradual release of ammonia further promotes the generation of pores in the composite material. Cooperating with the relatively low viscosity of furfuryl alcohol resin and the hydrogen bond connection between the hydroxyl group and the polar groups on the surface of the crushed powder material, it promotes the uniform penetration of the liquid phenolic resin, thereby improving the structural stability of the composite material. After carbonization, it ensures the compressive strength and pore uniformity of the carbon molecular sieve. The carbonization product of furfuryl alcohol resin forms oxygen-rich functional groups on the surface, preferentially adsorbing oxygen molecules, ensuring the nitrogen purity and increasing the nitrogen production rate. Moreover, the synergistic carbonization of furfuryl alcohol resin and tar can form a mesoporous-microporous gradient structure, reducing the oxygen-nitrogen ratio.

[0027] Preferably, the tar is composed of a tar liquid and a polyethylene glycol solution with a mass ratio of 1:0.05 - 0.1.

[0028] By adopting the above technical solution, the polyethylene glycol solution can adjust the viscosity of the tar liquid, reduce the flow resistance, improve the contact uniformity, thereby improving the particle uniformity of the carbon molecular sieve. Moreover, the pyrolysis of polyethylene glycol can form a mesoporous transition layer, reducing the gas diffusion resistance and increasing the nitrogen production rate. The tar liquid mainly controls the micropores to adsorb oxygen, and the mesoporous network of polyethylene glycol accelerates the desorption of nitrogen, thereby reducing the oxygen-nitrogen ratio. At the same time, the carbon skeleton of the tar cooperates with the interpenetration of the nano-carbon generated by the pyrolysis of polyethylene glycol to form a complementary reinforcement structure in the carbon molecular sieve, improving the compressive strength of the carbon molecular sieve.

[0029] Preferably, the diameter of the strip-shaped material of the extrusion is 1.1 - 1.5 mm, and the length is 1.5 - 3 mm.

[0030] By adopting the above technical solution, the short strip structure reduces the diffusion distance of gas molecules in the pores. Cooperating with the extrusion diameter, more uniform micropores can be formed during the carbonization shrinkage process, increasing the nitrogen production rate, reducing the oxygen-nitrogen ratio, and improving the compressive strength.

[0031] Preferably, the specific steps of the carbonization are as follows: First, carbonize at 300 - 400 °C for 0.5 - 1 h, then heat up to 500 - 650 °C and carbonize for 1 - 2 h, and finally heat up to 700 - 850 °C and carbonize for 2 - 3 h.

[0032] By adopting the above technical solution, preliminary carbonization is first carried out at 300 - 400 °C to ensure the uniformity of gas flow pores and the through - effect, in coordination with carbonization at 500 - 650 °C to promote the formation of pyrrole - N during nitrogen doping, and in coordination with subsequent carbonization at 700 - 850 °C to further improve the nitrogen doping stability and the carbonization uniformity, so that the finished carbon molecular sieve has the advantages of high mechanical strength, high particle uniformity, high nitrogen yield, and low air - nitrogen ratio.

[0033] Preferably, the specific steps of pore - tuning are as follows: Add 3 - 5% benzene and 3 - 5% water by weight percentage to the semi - finished product, and process it at 700 - 800 °C for 2 - 3 h.

[0034] By adopting the above technical solution, benzene volatilizes under high - temperature conditions, further increasing the gas overflow channels, ensuring the nitrogen yield, and reducing the air - nitrogen ratio; and the polycyclic aromatic hydrocarbons (such as graphite microcrystals) generated by the high - temperature pyrolysis of benzene are embedded in the carbon skeleton defect area through π - π stacking, improving the density uniformity of the carbon molecular sieve, thereby enhancing the compressive strength and particle uniformity of the carbon molecular sieve.

[0035] In summary, the present application has the following beneficial effects: 1. After the crushed flower mud is mixed with resin oil, tar, and water and carbonized, the carbon molecular sieve has the advantages of high particle uniformity, high compressive strength, high nitrogen yield, and small air - nitrogen ratio.

[0036] 2. Phenolic resin can generate a glassy carbon phase during carbonization, in coordination with the nitrogen - doped structure formed by the carbonization of polyethylene diamine, and the glassy carbon phase formed by the carbonization of furfuryl alcohol resin, which forms complementary reinforcement with the phenolic resin carbon skeleton. The nano - carbon whiskers formed by the pyrolysis of furfuryl alcohol resin penetrate into the pores, thereby further enhancing the compressive strength of the finished carbon molecular sieve.

[0037] 3. The combination of polyethylene diamine solution, polyethylene glycol solution, and furfuryl alcohol resin further improves the internal connected porosity of the carbon molecular sieve, increases the nitrogen yield of the carbon molecular sieve, and reduces the air - nitrogen ratio. Specific embodiments

[0038] The following further elaborates on the present application with reference to examples.

[0039] Preparation example of cellulase complex solution Among the following raw materials, cellulase was purchased from Shandong Pingju Biotechnology Co., Ltd.; other raw materials are all commercially available.

[0040] Preparation example 1: The cellulase complex solution was prepared by the following method: Mix cetearyl alcohol and cellulase in a mass ratio of 1:3 and stir evenly. The average particle size of the cellulase is 80 μm. Then, heat it to 51 °C and treat for 2 min, and then cool it to room temperature of 25 °C to obtain a cellulase composite. Mix the cellulase composite and water in a mass ratio of 1:70 and stir evenly to obtain a cellulase composite solution.

[0041] Preparation Example 2: The difference between this preparation example and Preparation Example 1 is that: Mix cetearyl alcohol and cellulase in a mass ratio of 1:2 and stir evenly. Then, heat it to 50 °C and treat for 3 min, and then cool it to room temperature of 25 °C to obtain a cellulase composite. Mix the cellulase composite and water in a mass ratio of 1:60 and stir evenly to obtain a cellulase composite solution.

[0042] Preparation Example 3: The difference between this preparation example and Preparation Example 1 is that: Mix cetearyl alcohol and cellulase in a mass ratio of 1:4 and stir evenly. Then, heat it to 52 °C and treat for 1 min, and then cool it to room temperature of 25 °C to obtain a cellulase composite. Mix the cellulase composite and water in a mass ratio of 1:80 and stir evenly to obtain a cellulase composite solution.

[0043] Preparation Example of Tar The following raw materials are all commercially available.

[0044] Preparation Example 4: Tar is prepared by the following method: Weigh 1 kg of tar liquid and mix it evenly with 0.08 kg of polyethylene glycol solution. The polyethylene glycol solution is a 2% mass fraction polyethylene glycol ethanol solution with an ethanol mass fraction of 95%, and the polyethylene glycol is polyethylene glycol 800 to obtain tar.

[0045] Preparation Example 5: The difference between this preparation example and Preparation Example 4 is that: Weigh 1 kg of tar liquid and mix it evenly with 0.05 kg of polyethylene glycol solution to obtain tar.

[0046] Preparation Example 6: The difference between this preparation example and Preparation Example 4 is that: Weigh 1 kg of tar liquid and mix it evenly with 0.1 kg of polyethylene glycol solution to obtain tar. Examples

[0047] The following raw materials are all commercially available.

[0048] Example 1: A processing method of carbon molecular sieve: S1. The flower mud is preliminarily pulverized to obtain flower mud particles. The carbon content of the flower mud is 78 - 80%, the average particle size of the flower mud particles is 40 μm. The cellulose enzyme composite solution prepared in Preparation Example 1 is added, and the mass ratio of the flower mud particles to the cellulose enzyme composite solution is 1:10. Ultrasonic dispersion treatment is carried out at 20 kHz for 35 min, then the temperature is raised to 95 °C and treated for 8 min. Then, ethanol with a mass fraction of 75% is added for washing 3 times, and the flower mud particles are filtered out, and the ethanol is filtered out to obtain a pre-treated material; A hydrochloric acid solution with a concentration of 4% is added to the pre-treated material, the solvent is water, and it is stirred at a rotation speed of 500 r / min for 20 min. After mixing evenly, the hydrochloric acid solution is filtered out, washed with water 3 times, dried by air drying, and then subjected to secondary ball milling and pulverization to obtain pulverized materials, and the average particle size of the pulverized materials is 1.5 μm; S2. 38 kg of pulverized material is mixed with 30 kg of water, stirred evenly at a rotation speed of 1000 r / min, and 0.72 kg of polyethylene diamine solution is added. The polyethylene diamine solution is a polyethylene diamine ethanol solution with a mass fraction of 1%, and the mass fraction of ethanol is 95%. Ultrasonic dispersion is carried out at 20 kHz for 10 min. After mixing evenly, 10.8 kg of liquid phenolic resin and 0.48 kg of furfuryl alcohol resin are added and mixed evenly. Finally, 20 kg of tar prepared in Preparation Example 4 is added and mixed and stirred evenly to obtain a composite material; The resin oil includes liquid phenolic resin, polyethylene diamine solution and furfuryl alcohol resin; S3. The composite material is extruded into strips. The average diameter of the extruded strips is 1.2 mm and the average length is 2 mm. Then carbonization is carried out. First, carbonization is carried out at 350 °C for 1 h, then the temperature is raised to 600 °C and carbonized for 1.5 h, and finally the temperature is raised to 800 °C and carbonized for 2.5 h to obtain a semi-finished product; 4% by weight of benzene and 4% of water are added to the semi-finished product, and then it is treated at 750 °C for 2.5 h to complete pore adjustment and obtain the finished carbon molecular sieve.

[0049] Example 2: The difference between this example and Example 1 is that: S1. The flower mud is preliminarily pulverized to obtain flower mud particles. The carbon content of the flower mud is 75 - 78%, the average particle size of the flower mud particles is 40 μm. The cellulose enzyme composite solution prepared in Preparation Example 2 is added, and the mass ratio of the flower mud particles to the cellulose enzyme composite solution is 1:10. Ultrasonic dispersion treatment is carried out at 20 kHz for 30 min, then the temperature is raised to 80 °C and treated for 10 min. Then, ethanol with a mass fraction of 75% is added for washing 2 times, and the flower mud particles are filtered out, and the ethanol is filtered out to obtain a pre-treated material; A hydrochloric acid solution with a concentration of 3% is added to the pre-treated material, the solvent is water, and it is stirred at a rotation speed of 500 r / min for 20 min. After mixing evenly, the hydrochloric acid solution is filtered out, washed with water 3 times, dried by air drying, and then subjected to secondary ball milling and pulverization to obtain pulverized materials, and the average particle size of the pulverized materials is 2 μm; S2. Mix 40 kg of crushed material with 35 kg of water, stir evenly at a rotation speed of 1000 r / min, add 0.2 kg of polyethylene diamine solution. The polyethylene diamine solution is a polyethylene diamine ethanol solution with a mass fraction of 1%, and the mass fraction of ethanol is 95%. Carry out ultrasonic dispersion for 10 min under the condition of 20 kHz. After mixing evenly, add 9.2 kg of liquid phenolic resin and 0.6 kg of furfuryl alcohol resin and mix. Stir evenly, and finally add 15 kg of the tar prepared in Preparation Example 5, mix and stir evenly to obtain a composite material; the resin oil includes liquid phenolic resin, polyethylene diamine solution and furfuryl alcohol resin; S3. Extrude the composite material. The average diameter of the extruded strip is 1.5 mm and the average length is 3 mm. Then carry out carbonization. First, carbonize at 300 °C for 1 h, then heat up to 500 °C and carbonize for 2 h, and finally heat up to 700 °C and carbonize for 3 h to obtain a semi-finished product; add 3% by weight of benzene and 3% of water to the semi-finished product, and then treat at 700 °C for 3 h to complete pore adjustment and obtain the finished carbon molecular sieve.

[0050] Example 3: The difference between this example and Example 1 is that: S1. Carry out preliminary crushing on the flower mud to obtain flower mud particles. The carbon content of the flower mud is 78 - 80%, the average particle size of the flower mud particles is 40 μm. Add the cellulase composite solution prepared in Preparation Example 3. The mass ratio of the flower mud particles to the cellulase composite solution is 1:10. Carry out ultrasonic dispersion treatment for 40 min under the condition of 20 kHz, heat up to 100 °C and treat for 6 min, then add ethanol with a mass fraction of 75% and wash 3 times. Filter out the flower mud particles, filter out the ethanol to obtain a pretreated material; add a hydrochloric acid solution with a concentration of 5% to the pretreated material, the solvent is water, stir at a rotation speed of 500 r / min for 20 min, after mixing evenly, filter out the hydrochloric acid solution, wash 3 times with water, dry by air drying, and then carry out secondary ball milling and crushing to obtain crushed powder, and the average particle size of the crushed powder is 1 μm; S2. Mix 35 kg of crushed material with 25 kg of water, stir evenly at a rotation speed of 1000 r / min, add 1.5 kg of polyethylene diamine solution. The polyethylene diamine solution is a polyethylene diamine ethanol solution with a mass fraction of 1%, and the mass fraction of ethanol is 95%. Carry out ultrasonic dispersion for 10 min under the condition of 20 kHz. After mixing evenly, add 12.9 kg of liquid phenolic resin and 0.6 kg of furfuryl alcohol resin and mix. Stir evenly, and finally add 25 kg of the tar prepared in Preparation Example 6, mix and stir evenly to obtain a composite material; the resin oil includes liquid phenolic resin, polyethylene diamine solution and furfuryl alcohol resin; S3. The composite material is extruded into strips. The average diameter of the extruded strips is 1.1 mm, and the average length is 1.5 mm. Then it is carbonized. First, it is carbonized at 400 °C for 0.5 h, then the temperature is raised to 650 °C and carbonized for 1 h, and finally the temperature is raised to 850 °C and carbonized for 3 h to obtain a semi-finished product. 5% by weight of benzene and 5% by weight of water are added to the semi-finished product, and then it is treated at 800 °C for 2 h to complete pore adjustment, obtaining the finished carbon molecular sieve.

[0051] Example 4: The difference between this example and Example 1 is that: The process of flower mud crushing treatment is direct crushing; that is, no cellulase complex solution is added during the process, nor is it treated with hydrochloric acid solution.

[0052] Example 5: The difference between this example and Example 1 is that: Cetearyl alcohol is not added to the cellulase complex solution during the process of flower mud crushing treatment.

[0053] Example 6: The difference between this example and Example 1 is that: The resin oil is liquid phenolic resin, that is, furfuryl alcohol resin and polyethylene diamine solution are not added.

[0054] Example 7: The difference between this example and Example 1 is that: Polyethylene glycol solution is not added to the tar.

[0055] Example 8: The difference between this example and Example 1 is that: The carbonization temperature for carbonization is 800 °C for 5 h.

[0056] Performance detection test 1. Nitrogen yield detection The carbon molecular sieves are prepared respectively by the methods of Examples 1 - 8. Referring to HG / T4364 - 2020, under the condition of a standard pressure of 0.8 MPa, the nitrogen yield is recorded.

[0057] 2. Air-nitrogen ratio detection The carbon molecular sieves are prepared respectively by the methods of Examples 1 - 8, and the air-nitrogen ratio is calculated.

[0058] 3. Uniformity detection The carbon molecular sieves are prepared respectively by the methods of Examples 1 - 8, and sieved. Record the proportion of carbon molecular sieves with a particle diameter of 1.1 - 1.2 mm. The total amount of carbon molecular sieve particles is 10,000, and record the proportion data. The higher the proportion, the higher the particle uniformity.

[0059] 4. Compressive strength detection The carbon molecular sieves are prepared respectively by the methods of Examples 1 - 8. Referring to HG / T4364 - 2020, the compressive strength is recorded.

[0060] Table 1 Performance Test Table

[0061] Combined with Examples 1-3 and Table 1, it can be seen that by utilizing the penetration and adhesion effects of resin oil and tar, structural defects caused by uneven local bonding during the carbonization process can be avoided, thereby further ensuring the particle uniformity of the carbon molecular sieve. Moreover, during the high-temperature carbonization process, a three-dimensional crosslinked network can be formed by polycondensation, improving the bonding force between particles, thus enhancing the compressive strength. Additionally, the interconnected microporous structure formed by the carbonization of resin oil and tar further increases the nitrogen production rate of the carbon molecular sieve and reduces the oxygen-nitrogen ratio.

[0062] Combined with Example 1 and Examples 4-8 and Table 1, it can be seen that in Example 4, the flower mud pulverization process is direct pulverization; that is, no cellulase complex solution is added during the process, and it is not treated with hydrochloric acid solution. Compared with Example 1, the nitrogen production rate of the carbon molecular sieve prepared in Example 4 is lower than that in Example 1, the oxygen-nitrogen ratio is higher than that in Example 1, the particle uniformity is lower than that in Example 1, and the compressive strength is lower than that in Example 1. This shows that the addition of the cellulase complex solution and hydrochloric acid can reduce the crosslinking resistance of the flower mud fibers, ensure particle uniformity, and can remove impurities, promoting the penetration of resin oil and tar into the fiber network, thereby enhancing the compressive strength of the carbon molecular sieve. After the substances in the flower mud are decomposed by the fiber bundle enzyme complex solution, they are more easily carbonized, making the carbon molecular sieve have a higher porosity and adsorption effect, and further increasing the nitrogen production rate and reducing the oxygen-nitrogen ratio.

[0063] In Example 5, cetearyl alcohol is not added to the cellulase complex solution during the flower mud pulverization process. Compared with Example 1, the nitrogen production rate of the carbon molecular sieve prepared in Example 5 is lower than that in Example 1, the oxygen-nitrogen ratio is higher than that in Example 1, the particle uniformity is lower than that in Example 1, and the compressive strength is lower than that in Example 1. This shows that while cetearyl alcohol facilitates the uniform contact of cellulase with the flower mud, and in combination with ethanol washing, its good lubricating fluidity facilitates the detachment of cellulase from the flower mud, thereby ensuring the porosity and particle uniformity of the carbon molecular sieve, and can also ensure the penetration of resin oil, ensuring that the carbon molecular sieve has a relatively high compressive strength.

[0064] In Example 6, the resin oil is liquid phenolic resin, that is, furfuryl alcohol resin and polyethylene diamine solution are not added. Compared with Example 1, the nitrogen production rate of the carbon molecular sieve prepared in Example 6 is lower than that in Example 1, the oxygen-nitrogen ratio is higher than that in Example 1, the particle uniformity is lower than that in Example 1, and the compressive strength is lower than that in Example 1. This shows that when furfuryl alcohol resin and polyethylene diamine solution are combined, the fluidity of furfuryl alcohol resin facilitates the entry of polyethylene diamine solution and liquid phenolic resin into the internal pores of the flower mud. In combination with the nitrogen doping effect of polyethylene diamine solution, it further increases the nitrogen production rate, reduces the oxygen-nitrogen ratio, and can also enhance the compressive strength and ensure particle uniformity.

[0065] In Example 7, polyethylene glycol solution was not added to the tar. Compared with Example 1, the nitrogen yield of the carbon molecular sieve prepared in Example 7 was lower than that in Example 1, the air-nitrogen ratio was higher than that in Example 1, the particle uniformity was lower than that in Example 1, and the compressive strength was lower than that in Example 1. This shows that the polyethylene glycol solution has good fluidity. During the carbonization process, the gas overflows evenly, ensuring the porosity of the carbon molecular sieve, making the carbon molecular sieve have the advantages of high nitrogen yield, low air-nitrogen ratio, and high particle uniformity. Moreover, the polyethylene glycol solution promotes the tar to enter the inside of the flower mud, thereby improving the compressive strength of the finished carbon molecular sieve. At the same time, the dispersion effect of polyethylene glycol ensures the particle uniformity.

[0066] In Example 8, carbonization was carried out at a carbonization temperature of 800 °C for 5 h. Compared with Example 1, the nitrogen yield of the carbon molecular sieve prepared in Example 8 was lower than that in Example 1, the air-nitrogen ratio was higher than that in Example 1, the particle uniformity was lower than that in Example 1, and the compressive strength was lower than that in Example 1. This shows that staged carbonization can ensure the generation of pyridine-N with a nitrogen-doped structure, while ensuring the nitrogen-doping effect. At the same time, staged carbonization by temperature can avoid cracking or pore collapse caused by the violent release of moisture and volatile components, ensure the pore size uniformity of the carbon molecular sieve, make the carbon molecular sieve have high compressive strength, nitrogen yield, and particle uniformity, and reduce the air-nitrogen ratio.

[0067] This specific embodiment is only an interpretation of the present application and does not limit the present application. After reading this specification, those skilled in the art can make modifications to this embodiment without creative contributions as needed, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A processing method of carbon molecular sieve, characterized in that, It includes the following steps: S1. The flower mud is crushed to obtain crushed powder materials; S2. Weigh 30 - 40 parts of the crushed powder materials, 10 - 15 parts of resin oil, 15 - 25 parts of tar, and 25 - 35 parts of water according to the mass ratio, and mix and stir evenly to obtain a composite material; S3. The composite material is extruded into strips and carbonized to obtain semi-finished products, and the semi-finished products are pore-adjusted to obtain finished carbon molecular sieves.

2. The processing method of a carbon molecular sieve according to claim 1, characterized in that: The specific steps of the S1 flower mud crushing treatment are as follows: The flower mud is preliminarily crushed to obtain flower mud particles, a cellulase composite solution is added, ultrasonic dispersion treatment is carried out for 30 - 40 min, the temperature is raised to 80 - 100 °C and treated for 6 - 10 min, then ethanol is added for washing 2 - 3 times, the ethanol is filtered out, then a hydrochloric acid solution with a concentration of 3 - 5% is added, after stirring evenly, the hydrochloric acid solution is filtered out, and it is washed with water, dried, and secondarily ball-milled and crushed.

3. The processing method of a carbon molecular sieve according to claim 2, characterized in that, In the S1, the carbon content of the flower mud is 75 - 80%, and the average particle size of the crushed powder materials is 1 - 2 μm.

4. The processing method of a carbon molecular sieve according to claim 2, characterized in that, The cellulase composite solution is prepared by the following method: Cetearyl alcohol and cellulase are mixed and stirred evenly according to the mass ratio of 1:2 - 4, then the temperature is raised to 50 - 52 °C and stirred for 1 - 3 min, and then cooled to room temperature to obtain a cellulase composite material; the cellulase composite material and water are mixed and stirred evenly according to the mass ratio of 1:60 - 80 to obtain a cellulase composite solution.

5. The processing method of a carbon molecular sieve according to claim 1, characterized in that The resin oil contains the following raw materials in parts by weight: 86 - 92 parts of liquid phenolic resin, 4 - 6 parts of furfuryl alcohol resin, and 2 - 10 parts of polyethylene diamine solution.

6. The processing method of a carbon molecular sieve according to claim 5, characterized in that, In the S2, after the crushed materials are mixed with water, a polyethylene diamine solution is added, ultrasonic dispersion is carried out evenly, then liquid phenolic resin and furfuryl alcohol resin are added and mixed and stirred evenly, and finally tar is added and mixed and stirred evenly to obtain a composite material.

7. A processing method of a carbon molecular sieve according to claim 1, characterized in that, The tar is composed of a tar liquid and a polyethylene glycol solution with a mass ratio of 1:0.05 - 0.

1.

8. A processing method of a carbon molecular sieve according to claim 1, characterized in that, The diameter of the extruded strip is 1.1 - 1.5 mm, and the length is 1.5 - 3 mm.

9. A processing method of a carbon molecular sieve according to claim 1, characterized in that, The specific steps of the carbonization are as follows: First, carbonize at 300 - 400 °C for 0.5 - 1 h, then raise the temperature to 500 - 650 °C and carbonize for 1 - 2 h, and finally raise the temperature to 700 - 850 °C and carbonize for 2 - 3 h.

10. A processing method of a carbon molecular sieve according to claim 1, characterized in that, The specific steps of the pore adjustment are as follows: The semi-finished products are added with 3 - 5% of benzene and 3 - 5% of water by weight percentage, and treated at 700 - 800 °C for 2 - 3 h.

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